1. Field of the Invention
The present invention relates to a saw and more particularly, to a saw having a dust collection system.
2. Description of the Related Art
Referring to FIGS. 8 and 9, a miter saw 80 having a dust collection system typically includes a table assembly 81, a pivot arm 82 which is pivotally mounted to the table assembly 81, a driver 83 mounted on the pivot arm 82, and a saw blade 84 driven by the driver 83 to rotate. When a user wants to execute a cut on a workpiece (not shown) disposed upon the table assembly 81, the user firstly empowers the driver 83 to rotate the saw blade 84, and secondly rotates the pivot arm 82 downward toward the table assembly 81, such that the saw blade 84 is conducted downward toward the table assembly 81 and cuts through the workpiece.
A dust collection passage 85 is formed within the pivot arm 82 and is located adjacent to where the pivot arm 82 is pivotally mounted to the table assembly 81. An inlet 852 of the dust collection passage 85 is located in an extended position along a tangent line in the direction L of where the saw blade 84 rotates out of the workpiece. An outlet (not shown) of the dust collection passage 85 then is designed to be attached a dust bag 86 or a vacuum (not shown). During a cutting operation, sawdust or chips of the workpiece cut by the saw blade 84 are propelled to enter the inlet 852 of the dust collection passage 85 by the centrifugal force and the airflow generated by the rotating saw blade 84. Thus, the sawdust and/or chips enter the dust bag 86 through the dust collection passage 85. By this way, the miter saw 80 can achieve the goal of collecting sawdust and/or chips through the dust collection passage 85.
However, there is an open area P between the inlet 852 of the dust collection passage 85 and where the saw blade 84 rotates out of the workpiece. The airflow generated by the rotating saw blade 84 is dispersed easily within the open area P, such that some portion of the sawdust and/or chips spread in the airflow are not completely propelled into the inlet 852 of the dust collection passage 85 but are dispersed onto the table assembly 81 and into the surrounding areas. The result is a reduction in sawdust collection efficiency and a dirty working space.